Gubbiotti



July 16, 1963 GUBBIOTT] 3,097,538

MECHANICALLY OPERATING CONTINUOUS SPEED VARIATOR Filed Dec. 2, 1960 4Sheets-Sheet 1 All;

INVENTOR. L] No GU 88/ OT BY W ATTORNEYS L. GUBBIOTTI July 16 1963MECHANICALLY OPERATING CONTINUOUS SPEED VARIATOR 4 Sheets-Sheet 2 FiledDec. 2, 1960 h an 2! 3 N N U 4 4 INVENTOR. LINU GUBBIOTT/ BY WM A T To RN EYS L. GUBBIOTTI 3,097,538 MECHANICALLY OPERATING CONTINUOUS SPEEDVARIATOR July 16, 1963 4 Sheets-Sheet 3 Filed Dec. 2, 1960 INVENTOR LINOGUBBIOTTI BY W WM? M ATTORNEYS L. GUBBIOTTI 3,097,538 MECHANICALLYOPERATING commuous SPEED VARIATOR July 16, 1963 4 Sheets-Sheet 4 FiledDec. 2, 1960 NT RT a i w T NT INVENTOR L IMO GUBB/OTTI AT ORNEYS3,997,538 Patented July 16, 1963 ice Italy Filed Dec. 2, 1960, Ser. No.73,250 Claims priority, application Italy Jan. 11, 1960 4 Claims. (Cl.74-112) The present invention relates to a continuous speed variator.

The purpose of this invention is to provide a continuous speed variatorthe operation of which is exclusively mechanical, in order to obtain anetliciency far higher than that obtainable by hydraulic variators.

Another purpose of this invention is to provide a variator of the citedkind, suitable to be mounted either on industrial machines or to be usedwith the drive of vehicles. In the latter case, the variator accordingto this invention makes it possible to dispense with the friction clutchand the differential.

According to this invention, a unit is provided comprising, incombination, an input shaft to which the motive power is applied, acylindrical drum rigid with said shaft and internally provided with acircular cross-section eccentric recess, a sleeve received in therecess, and also provided with an eccentric recess the eccentricity ofwhich is equal to that of the cylindrical, a further sleeve having anannular cross-section mounted in said cylindrical recess of saidfirst-mentioned sleeve, an output shaft received in said further sleeve,andprovided with cross-seatings, means allowing said further sleeve tomake translational movements, but preventing said sleeve from rotatingabout its axis, thrust elements mounted in said seatings to transmit themovement of said annular cross-section sleeve to the output shaft, andmeans for changing at will the relative position of the two eccentricrecess cylinders and therefore the drive ratio.

This invention will be hereinafter described with reference to theattached drawings showing an embodiment of the invention, only by way ofexample:

In the drawings:

FIG. 1 is a side view of the variator partially in cross section andtaken along a vertical plane;

FIG. 2 is a cross-sectional view taken along the plane II-II of FIG. 1;

FIG. 3 is a cross-sectional view taken along the plane TIL-III of FIG.1;

FIG. 4 is a partial cross-sectional view taken along the line IVIV ofFIG. i1;

FIG. 5 is a cross-sectional View taken along the plane V-V of FIG. 4;

FIG. 6 is a cross-sectional view taken along the plane VIVI of FIG. 3;

FIG. 7 is a side view of the output shaft, partially in cross-sectionand taken along an axial longitudinal plane;

FIGS. 7A, 7B, 7C, 7D, 7E show, in the cited order, the cross-sectionalviews corresponding to the planes A-A, BB, C-C, D-D and EE,respectively;

FIG. 8 shows the detail, on an enlarged scale, one of the thrustelements;

FIG. 9 is a side View of the detail of FIG. 8, and

FIG. 10' is a cross-sectional view taken along the plane XX of FIG. 9.

With reference to FIGS. 1 to 3, the input shaft 1 is connected to aprime mover of any type, not shown.

The shaft 1 is journaled in a roller bearing 2 supported by a case 3provided with a bed plate 4, and terminates in a flange 5 to which, bymeans of a set of screws 6, is fixed a first cylindrical drum 7internally provided with a circular cross-section eccentric bore 8.

Within said bore 8 is rotatably mounted a second cylindrical drum 9,which is also provided with an internal eccentric bore 10 into which atubular sleeve 11 is inserted.

The drum 9 and the sleeve 11 are immersed in an oil bath, the oil forwhich is fed into the drum 7 through an aperture closed by means of thescrew 16.

The front portion of the drum 7 is connected to the collar 12 which inturn is rotatably mounted on the hollow hub 14 by means of the rollerbearing 13. Between said two elements a seal ring .15 is inserted havingthe function of preventing the lubricating oil from escaping. The hollowhub 14, in turn is fixed rigidly by a lock screw 17 to a cap 18 which isfastened to the case '3 by the bolts 19. A roller bearing 21 is mountedbetween the hollow hub 14 and the cap 18, and said roller bearing, inthe conditions shown in FIG. 1 is inoperative because of the lock screw17 fixing the hub 14 rigid with the case 3, as aforesaid.

The tubular sleeve 11 is fixed by the screws 21 to a bushing 22 formingpart of a double slider coupling (shown also in FIGS. 4 and 5) whichbushing is provided with two front dogs 23 on diametrically oppositesides of the axis of sleeve 11. Two other front dogs 24 on the oppositeends of a diameter at to the alignment of dogs 23 are carried by thehollow hub 14 forming a second part of the coupling (FIG. 5). Said pairsof front dogs, enter corresponding notches 25 of a ring 26, which formsthe third part of the coupling, and having the function of preventingthe tubular sleeve 11 from rotating about its axis, although allowing alimited transverse translation movement of said sleeve.

Concentrically with the hub 14 (FIG. 1) is mounted the output shaftgenerally denoted at 2.7 to which the resistant torque is applied. Theoutput shaft 27 is supported by the pair of ball bearings 28 spacedapart by the spacer 29, and by the bearing 30 mounted at the inner endof the shaft, near the flange 5. A set of transverse seats 31 (FIGS. 7to 7E) parallel to one another is provided in the shaft 27 and saidseats are equiangularly spaced around the output shaft. In theillustrated example, there are five seats 3-1 angularly spaced from eachother by 72. In each transverse seat 31 is positioned a thrust elementgenerally denoted at 32, said thrust element being shown in detail inFIGS. 8 to 10. Each element 32 has a length slightly less than thediameter of the inner periphery 33 of the tubular sleeve 11 and the endsof said element 32 are shaped to match the contour of the innerperiphery 3 3. The body 32 of the thrust element is provided with aninner groove 34 wherein is received a set of rollers 35 on which rests asliding block 36 slidable between two end abutments 37 and 38. Thesliding block 36 is provided with a little notch 39 in which rests thetooth 46 on the corresponding seat of the shaft 27.

In order to ensure the continuity of the contract between each thrustelement and the associated tooth 40, on the opposed sides of each seat31 is provided a periph eral groove 41 and in each groove 41 ispositioned a helical spring 42. Each pair of springs 42 is fastened atone of its ends to a cross-member 43, while the other end carries a pin44 resting against the rear surface of the thrust element 32 urging thesliding block 36 against the corner 40.

A vertical projection 45 is provided in the upper portion of the case 3,and in said projection is positioned a stem 46 carrying a hand wheel 47and connected by a knuckle 48 to a threaded bolt 49 (FIGS. 1 and 2). Thelatter is threaded into a nut 50 connected by the stud 51 to a fork 52carried by the rocking lever 53 the pivot pin 54 of which is capable ofsliding in an elongated hole 55 in a member 55a mounted in projection45. The lower end of the lever 53 is provided with another fork 56 theends of which are connected by the pins 57 to the bushing 58 mounted onthe bearing 5i The latter is mounted on the collar 60 which is providedwith the plain bearing 61 through which passes the shaft 1.

The collar 60 is bodily connected to the yoke 62 (FIG. 6) at the ends ofwhich are mounted the two pins 63 slidable in seats 64 provided in thedrum 7. The pins 63 terminate in two oblique teeth 65 which are engagedin helical guide grooves 66 provided on the outer periphery of the drum9.

The device operates as follows:

When the hand wheel 47 (or an analogous control, for instance a handoperated lever) is operated, the rocking lever 53 is caused to rotateabout [the pivot 54 causing in turn a sliding movement of the bushing 58and of the collar 60- with the yoke 62 on the shaft 1.

The pins 63 slide in the seats 64 provided in the drum 7, and theirteeth 65, guided in the grooves 66, rotate the drum 9 with respect tothe drum 7 which, being directly coupled to the shaft 1, rotates withthe latter. Summarizing, the operation of the hand wheel 47 has theeffect of changing the relative position of the drums 7 and 9 whichsimultaneously rotate, driven by the shaft 1, to which the drivingtorque is applied.

The drums 7 and 9 are provided with inner recesses the eccentricities ofwhich are equal, whereby when the positions of the drums is that shownin FIG. 3, the two eccentricities compensate for each other, and thetubular sleeve 11 is thereby perfectly centered and does not rotateabout its axis being held by the ring 26. Under these conditions, theoutput shaft 27 is stationary.

When the relative position of the drums 7 and 9 is changed by the handwheel 47, the inner circular bore of the drum 9 takes an eccentricposition whereby the sleeve 11, driven by the unit of the drums 7 and 9,always with no rotational movement about its axis, moves along acircular translation path, with a radius corresponding to the diiferencein eccentricity between the drums 7 and 9.

In other words, the movement of the sleeve .11 causes its axis (to movealong a circular path. Assuming that this movement occurs clockwisestarting from the position shown in FIG. 7A, a thrust action of thethrust element 32 occurs against the corner 40 of the output shaft 27.The tangential component generated by said action is converted into asliding movement of the sliding block 36 while the component at rightangles to the sliding block 36 causes a rotation of the output shaft 27through an angular distance corresponding to the stage of active thrustof the considered element, said stage being 72. Before the presentlyconsidered thrust element has completed its active stage, the subsequentthrust element (FIG. 7B) starts operating through a further sector of 72and so on so that through a complete revolution of the bore 33 of thesleeve 11, the sequential action of the five thrust elements against therespective corners '46 of the output shaft 27 is obtained. The angularspeed of rotation of said shaft 27 is determined by the crank armdepending upon the distance of the path of the circular translationmovement of the sleeve 11 from the axis of output shaft 27 and increasestherefore with the increase of the difference of eccentricity of thedrums 7 and 9', and said difference can be changed by the control means47. Thus the possibility is provided to change gradually the speed fromzero up to the maximum speed of the output shaft 27, and said maximumspeed of the output shaft being obtained when the teeth 65 of the pins63 reach the end of the helical guide grooves 66. When the thrustelements 3 2 are out of their active stage, i.e. are not pressed againstthe corner 40, the continuity of the contact between the sliding block36 and the corner 40 is ensured by the springs 42, as aforesaid. Underthese conditions, the thrust elements rotate with a slight frictionalsliding movement on the inner surface of the sleeve 11.

g In order also to obtain from the variator the function of a,differential, it will be sufficient to loosen the lock screw 17 and thenthe hollow hub can also rotate. in this case it will be possible also toapply a resistant torque to the hub 14- and any change of speed ofeither of the elements 14 or 27 will have the effect of causing areverse variation of the speed of the other element, like theconveutional type differentials.

The present invention has been illustrated and described in onepreferred embodiment, but it is intended that construotive variationsmay be practically adopted without departing from the scope of thepresent invention as defined in the appended claims.

I claim:

1. In a mechanically operating continuous speed variator with an inputshaft adapted to be connected to a prime mover and having a firstcylindrical drum fixed to said shaft and having an internal circulareccentric bore and two opposed longitudinal recesses at the front endthereof, a second drum positioned in said bore and also having acircular eccentric bore with an eccentricity equal to that of said firstdrum and having helical guide means on its outer surface, a unitcomprising in combination an annular sleeve mounted in the bore of saidsecond drum, a collar fixed on said sleeve, an output shaft aligned withsaid sleeve, a tooth on said output shaft, a hollow hub carrying saidoutput shaft, a double slider coupling connecting said sleeve to saidhollow hub and allowing translational movements of said sleeve,hindering rotational movement thereof about its axis, said output shafthaving recessed transverse seats therein, a thrust element mounted ineach of said transverse seats for transmitting the movement of saidannular sleeve to said output shaft, said thrust elements each having alongitudinal groove and two end projections, rollers mounted in saidlongitudinal grooves, a sliding block slidably supported by said rollersbetween said end projections and having a notch therein, said seatshaving peripheral grooves in said output shaft on the sides of therecesses for said seats, helical springs mounted in said grooves, saidsprings bearing at one end on said output shaft and at other end on saidthrust elements, a casing in which the entire unit is mounted, and alock screw carried by said casing and engageable with said hollow hubfor blocking said hollow hub.

2. The combination as claimed in claim 1, in which said thrust elementsare bars extending crosswise with respect to said sleeve and mountedwithin said recesses for the transverse seats in said output shaft, saidbars being parallel to one another and equiangularly spaced a distanceequal to 360 divided by the number of said bars, said thrust elementsconverting a circular translational movement of said sleeve into arotational movement of said output shaft and acting sequentiallythereon.

3. The combination as claimed in claim 1, in which said double slidercoupling consists of a ring concentrical with said output shaft andhaving two pairs of notches located on lines at right angles, and twopairs of front dogs, one pair engaging in each groove, one pair of frontdogs being on said hollow hub and the other pair on said collar.

4. The combination as claimed in claim 1 and further comprising meansfor changing the relative position of said two drums, comprising acontrol hand wheel, a stem on which said hand wheel is mounted, avertical projection on said case in which said stem is positioned, athreaded bolt, a knuckle connecting said stem to said threaded bolt, anut fitting onto said threaded bolt, a rocking lever having fork-shapedupper and lower ends, a stud connecting the fork-shaped upper end ofsaid rocking lever to said nut, two plates each having an elongated holeand secured to the vertical projection of said case in positions opposedto one to another, a pivot pin having the ends slidably positioned insaid elongated holes of said plates, a bushing, two pins respectivelyconnecting the ends of the fork-shaped lower end of said rocking leverto said bushing, a bearing in which said bushing is mounted, a collarsupporting said bearing, a

yoke rigidly connected to said collar, a pin at each end of said yokeand slidahle through said two opposed longitudinal recesses at the frontend of said cylindrical drum, said guide means on said second drum beinghelical grooves, the ends of said pins engaging in said helical guidegrooves of said second drum, whereby when said control hand wheel isrotated said rocking lever is caused to rock about said pivot pincausing in turn a sliding movement of said bushing and collar with saidyoke on said input shaft, and said pins sliding in said opposedlongitudinal recesses of said first drum rotate said second drum withrespect to said first drum during rotation of said input shaft by meansof the ends of said pins engaging in said helical grooves.

References Cited in the file of this patent UNITED STATES PATENTS NewmanNov. 21, Sharp Jan. 28, Weiss July 1, Conant Apr. 18, Foster Nov. 18,Dunn June 15, Hall Oct. 9, Greening Aug. 16, Seek Dec. 5, Hubner May 11,

1. IN A MECHANICALLY OPERATING CONTINUOUS SPEED VARIATOR WITH AN INPUTSHAFT ADAPTED TO BE CONNECTED TO A PRIME MOVER AND HAVING A FIRSTCYLINDRICAL DRUM FIXED TO SAID SHAFT AND HAVING AN INTERNAL CIRCULARECCENTRIC BORE AND TWO OPPOSED LONGITUDINAL RECESSES AT THE FRONT ENDTHEREOF, A SECOND DRUM POSITIONED IN SAID BORE AND ALSO HAVING ACIRCULAR ECCENTRIC BORE WITH AN ECCENTRICITY EQUAL TO THAT OF SAID FIRSTDRUM AND HAVING HELICAL GUIDE MEANS ON ITS OUTER SURFACE, A UNITCOMPRISING IN COMBINATION AN ANNULAR SLEEVE MOUNTED IN THE BORE OF SAIDSECOND DRUM, A COLLAR FIXED ON SAID SLEEVE, AN OUTPUT SHAFT ALIGNED WITHSAID SLEEVE, A TOOTH ON SAID OUTPUT SHAFT, A HOLLOW HUB CARRYING SAIDOUTPUT SHAFT, A DOUBLE SLIDER COUPLING CONNECTING SAID SLEEVE TO SAIDHOLLOW HUB AND ALLOWING TRANSLATIONAL MOVEMENTS OF SAID SLEEVE,HINDERING ROTATIONAL MOVEMENT THEREOF ABOUT ITS AXIS, SAID OUTPUT SHAFTHAV-